In July 2016, Newstapa, an online news outlet run by the Korea Center for Investigative Journalism, unveiled the videos and reported that the business tycoon paid money to suspected sex workers five times between December 2011 and June 2013 at his houses in southern Seoul.

In the video clips, conversations between a man, who appears to be Lee, and the women indicate that some sort of sexual services were transacted between them.

Late last month, prosecutors arrested Seon, 56, on charges of orchestrating the recording of the video clips and blackmailing Samsung.

Prosecutors are now looking into whether the money was sent by the group or from Lee's private funds.

Samsung earlier said the suspects approached the group seeking money, but it rejected the offer because their claim was not reliable.

Prosecutors on Monday raided the offices of the country's food and entertainment conglomerate CJ to investigate the group's possible involvement in producing the videos.

The nation's 14th largest business group, run by Lee's relatives, was part of Samsung Group before it broke off in 1993.

At the time of the recording, the two groups were involved in a dispute over assets left by Lee's father, Lee Byung-chull, who founded the group.

CJ Group has flatly denied its involvement, saying Seon resigned after he was arrested.

Prosecutors are also investigating if prostitution actually took place and if so, whether the conglomerate was involved in the process.

Lee has been hospitalized since May 2014 after suffering a heart attack.

His son and de facto leader of the group Lee Jae-yong was arrested last month over allegations of bribery in connection with a corruption scandal implicating former President Park Geun-hye and her friend. (Yonhap)